Compounded lubricant



I corrosivity, especially with respect to modern Patented June 18, 1940UNITED STATES PATENT OFFICE COMPOUNDED LUBRICANT ware No Drawing.Application February 23, 1937, Serial No. 127,192

2'! Claims.

This. invention relates to new and useful compositions of the compoundedmineral oil class. More particularly, it involves the provision of alubricating oil containing metal salts of organic acids and an additionagent which inhibits undesirableeflects of such compounds, as moreparticularly pointed out hereinafter, without destroying desiredbeneficial eflects obtained therefrom.

Metal salts of organic acids are known as compounding ingredients forlubricating oils and have been added thereto for various purposes. Forexample, aluminum oleate is disclosed as a dispersing agent for graphitein the U. 8. Patent to Burke #1,732,221; and various-soaps have beendisclosed as pour point depressing agents.

In its broader aspect this invention is applicable to compounded oils ofthe above types. However, the present invention is more particularlyconcerned with oils compounded with certain metal naphthenates such asaluminum or magnesium naphthenates to inhibit piston ring sticking.

An important property of lubricating oils is low bearing metals such ascopper-lead mixtures or cadmium-silver alloy. Some lubricating oilswhich have been entirely satisfactory from the standpoint of corrosivityto high grade Babbitt bearing metals show a corrosion rate withcadmium-silver and copper-lead bearings which is greater than thatpermissible. Lubricating oils containing metal soap compoundingingredients have been found in general to show undesirable corrosiveeffects on such bearing materials. However, these-metal soap compoundingingredients are highly desirable or even necessary for other purposes,-such as inhibitors for piston ring sticking.

Accordingly, it is an object of the invention to solve the abovedifliculties by providing an improved compounded mineral oil havinglittle or no corrosive action to machine parts and yet containing metalsalts of organic acids.

Another object of the invention is to inhibit corrosive eflects oicompounded lubricating oils containing metal salts of organic acids suchas metal naphthenates.

A still further object of the invention is to improve the wear reducingvalue of mineral oils compounded with metal salts such as naphthenates.

Another object of the invention is to increase the resistance tooxidation and discoloration of oils compounded with metal soaps.

In the investigation of lubricating oils containing metal salts oforganic acids such as metal naphthenates, it has been found thatoil-soluble organic compounds comprising an ester with a hydroxyl groupin the alpha or beta position relative to the carboxyl group materiallyimprove various properties of the compounded oils. These types ofcompounds may be represented generically by thefollowing structuralformulae:

Alpha hydroxy ester Rr-CH-GOB,

Beta hydroxy ester Br-O-O-OKr-CH-h RPOECHQCO-BI In these formulae R1 andR2 represent an alkyl,

aryl, aralkyl or cyclic non-benzenoid group. R; and B: may, of course,contain other active groupings and may be either of the same ordifferent types.

Attention is directed to the fact that in the above types of compoundsthe hydroxyl group is no more than two carbon atoms removed from thecarboxyl group. The addition of these types of esters to oils containingmetal soaps effectively inhibits the corrosive action of oils socompounded, but where the hydroxy] group is further removed than twocarbon atoms from the carboxyl group it has been our experience that theesters do not adequately inhibit the corrosive action of such oils. Theinferior inhibiting efiects obtained from these other types of hydroxyesters make it necessary to utilize an alpha or beta hydroxy ester inorder to obtain the fullest benefits of this discovery and invention. 4

Specific examples of esters which have been found eflective for reducingcorrosive efiects of eral lubricating oils containing metal naphthenatescomprise diethyl tartrate, dibutyltartrate, diamyl tartrate, di-isoamyltartrate, dibenzyl tartrate, dioctyl tartrate, dilauryl tartrate, amyllactate, octyl lactate, tri-isoamyl citrate, and diethyl mucate.

aeoaeoi ether and carefully wiped with a soft cotton cloth.-

At the same intervals the oils were tested for viscosity, A. S. T. M.naphtha. insolubles; and neutralization number to obtain their oxidationcharacteristics. The duration of the testwas Z2 To illustrate the effectof these esters as corhours. Summarized results are given in Tablerosion inhibitors, strip corrosion test data were #1.

TABLE #1 12 hours at 300 F.

Addition agents Weight loss in Type 01 oil grams Percent increase s {ahaNeut. cam viscosity No. Metal nnphthenate Ester fg? miumat silverWestern 011 (A) BAE 30- -None None. .0100 0 98 192 2.34 D0 1% likdlalinaphthenate (270 M. W. (10 .0870 1134 320 670 4.04

- 1% dibutyl tartrata- 025 0 0030 119 246 3. 60 a dlbutvl tartrate. 0258l 0055 94 l odiocty tertreteu .0584 .0449 123 3.39 1% diamy termite.0176 .0064 1% diethyr tartrate .0124 0124 259 438 4. 21 1% dibenzyltam-aw- 0230 0 33 3. 34 None .0475 .0001 293 3.06

Do- 1% dibutyl tam-ate 0040 0 123 187 2. 40 Pe gnsylvema motor 011 SAENone 1350 1620 72 2 2. 80 'Do 1% 1% ()iinaphthenate (210 M. w. -do .2087.2315 11s 5 4.30

361 S D0 do r- 1%dibutyl tartraten .0372 .2330 93 1 3-80 Penn. aviationoil SAE 60... None None 0874 .0453 20 0 D0 1% $1inaphthenate (270 M. W.do 1495 1702 74 4 8.01 S 0 do 1% dibutyl tartrate 0299 2225 56 3 Wggternmotor oil (A) SAE None Non .0100 0 98 192 2. 34 b0 1% naphthenate (270M. W. (lo .1391 1191 216 7 3- 0 am D0 do +1%dibutyltartrate .0366 .1331279 393 3.33 D0 1% naphthenate (340 M. W. None .2083 .0640 440 710 1 801D0 do +l% diamyltarttate .0122 .0003 329 447 5-8 W egtern motor on (B)SAE 1% L3; naphthenate 270 M. W. None .1353 .0629 112 183 4.9

aci D0 .l. do 1% diamyl tartrate" 0618 0056 139 3 9 3- 59 Blended Penn.and Western N n Nona .0523 o oil SAE 20.

D0 l\g naphthenate (270 M. W. de .1843 .0070 2 59 3.01 D do +1%dlamyltartrate. .0275 .0007 35 36 4 obtained on several mineral oilscompounded with 1% of-a metal naphthenate to which had been addeddifierent esters as taught in this invention. A basic aluminumnaphthenate containing 3 equivalent weights of aluminum to 2 equivalentweights of petroleum naphthenic acids, and magnesium naphthenate wereused as the metal naphthenate addition agents in these tests. Likewise,petroleum naphthenic acids having an'average molecular weight of 270,340, and 370 were used in various of the different tests to illustratethe relative efiects of the molecular weight of the naphthenic acids oncorrosiveness and other properties of the oil. v

The strip corrosion tests were carried out in the following manner:Glass tubes 2 inches in diameter and 20 inches long were immersed in anoil bath, the temperature of which was automatically controlled towithin '1 F. of the test temperature which was 300 F. Approximately 300c. c. of oil under the test was placed in each tube and air was bubbledthrough it at the rate of 10 liters per hour. Strips of the differenttypes of bearing metals were cut to size and.

placed in the oils; in most cases more than one type of metal was testedsimultaneously in the same sample of oil. The weight loss oi each stripThe results in Table 1 include a large number of combinations ofdifierent types of oils, various metal naphthenates and different typesof esters on two different bearing metals. It will be noted that someesters are more effective than others, and that the effectiveness of asingle" ester 4 varies with the mineral oil used, the naphthenatecontained therein and the bearing metal being tested. The dataillustrate the following facts:

(1) Oils from Western crudes are essentially noncorrosive.

(2) The addition of metal naphthenates such as aluminum dinaphthenate ormagnesium naphthenate increases the corrosiveness of mineral oils tocopper-lead and cadmium-silver bearlng metals.

(3) The addition of hydroxy esters such as disclosed in this inventionto oils containing these naphthenates markedly reduces theircorrosiveness to these bearing metals.

It has also. been found that oils containing naphthenates from theheavier acids and from the lighter acids do not difier greatly incorrosivenessbut that the corrosive action of oils containing soaps ofthe heavy acids may be more effectively inhibited by the esters. Thedata in Table 2 are of interest in this'respect.

TABLE #2 Weight loss (grams) in 72 hours at 300 F.

Oil

' Copper- Cadmiumlead silver Western oii-SAE 30 .0100 0 Western oil-SAE30+l% Al dinaph. (270 M. W. acid) .0670 .1134 Western Oil-SAE 30+l% Aldinaph.+l%

diamyl tartrate .0176 .0064 Western Oil-SAE 30+1% A] dinaph. (M0

M. W. ac .0475 0001 Western oil-SAE 30+i% Al dinaph.+l%

dibutyl tartrate 0040 0 Western oil-SAE 30+1% mag. naph. (270 M-W.aci.1391 .1191 Western oil-SAE 30-14% mag. naph.+l% w l? t flt'mie"""'fi"i&6'

es rno mag. na M. w. acid .1 .2 .2083 .0640 Western oil-SAE 30+l% mag.naph.+i%

diamyl tartrate 0122 0003 Investigation also shows that addition ofesters in accordance with this invention, to oils compounded withaluminum dinaphthenate very ma- It should be noted that wear consists oicorrosion and abrasion, and, strictly speaking. represents two difierenteffects. Corrosion is the result of chemical attack of ingredients inthe oil on the metal. This, of course, may occur on stationary parts andindependently of abrasion. 0n the other hand, wear may result primarilyfrom abrasion of the metal surface due to contact under load betweenmoving parts. Similarly this phenomenon may occur in the absence ofcorrosion. Most generally both eflects occur simultaneously in a runningengine and in order to more closely simulate such conditions a series oftests was run on a General Motors connecting rod machine, in which bothfactors, that is. high temj peratures causing accelerated corrosion andcontact between moving surfaces. are present. The

results of these tests are tabulated below.

TABLE #4 Efiects of esters for inhibiting corrosivity and notes (GeneralMotors connecting rod maabrdsion with oils containing metalnaphthaterially reduces the amount of wear and friction. chine) as. re:se:

w oss gms. 64 hours at W 1. Mineral oil stock Soap compound Inhibitor(ester) Copper-lead g g as: 270 M. W. acid .3. 17 dihutyl tartmte....4536 .2459 do 1 diamyl tartrate... .758) .7416 1% Al dinaph. (340 M.-W. acid).. 0.2% diamy} tartrate-. .0925 6237 17:c1 igagnesiumnaphthenate (340 M. W. 6.1912 ao 1% diamyltartrate.- 2.0m

Described Nat. Pet.- News, Nov. 11, 1936, Page 31.

Test results on 3 different types of laboratory machines are tabulatedbelow:

Teens #3 Effects of esters an oiliness of oils containing aluminumdinaphthenate asse t;

hours at 2 be. steel on bmgm' load rmmkan 5it./min.l76 F.

machine,"

steel on bronme, Wear-Mg block Relative temp., "F

Ball Cup Frlct. Wear Test oil No. 1 Test oil N0. 1% Al dinaph. (270 M.W. acids) Test oil No. 1 1% Al dinaph. 1% diamyl tartrata. Test oil No.2 Test oil No. 2 1'7 A1 dinaph. (270 M. W. acids) Test oil No. 2 1% Aldinaph. 1% dibutyl tattrate.. Test oil No. 3 Test oil No. 3 1'7 A1dinaph. (270 M. W. acids) Test oi] No. 3 1 0 Al dinaph. 56% diamyltartrate.

A laboratory wear testing machine comprising a 56-inch steel ballagainst a 34-inch steel cylinder which is rotated at 600 R. P. M. andwhich dipsin the 611 being tested. I

"Described in S. A. E. Journal, volume 28. page 63, 1932.

'Describcd in A. P. 1. Proceedings, mid-year 1032, section III, page 00(published by Petroleum Team #5- Mineral oil stock Soap compound r asymou a a laboratory tests, oil temp.: 108 and 279 F. a

Loss in weight per bearing for last 1,050 miles of a 2,925 mile runinhibitor (ester) Cadmiumsilver, grams Copperlead, 8

Blended lienn. and Western oil SAE 30.

1% $1 dinaph. (270 M. W. acid). o

. do 1% Al dinaph. (340 M. W. acid).

1% diamyl tartrate o 0.5% diamyl tartrate.

The tests in the 1935 Plymouth engine were made with the engine directlyconnected to an electric dynamometer, and the engine was run alternatelyhot and cold at the temperatures indicated in the table. In the coldpart of the cycle the speed was 1500 R. P. M. (30 miles per hour), theload was 5.9 horsepower, and four ounces of distilled water were addedat the start of the period to simulate conditions produced by densationof moisture in the crankcase. m

con-

were loaded with fan dynamometers. The jacket temperature was maintainedat 345 F. by the use of ethylene glycol in the water jackets and thecrankcase oil temperature was maintained at 220 F. with an electricheater. The results in Table No. illustrate clearly the beneficial cheatin preventing piston ring sticking which these oils give as comparedwith the same original uncompounded crankcase lubricant.

TABLE #0 Efiectiveness of oils containing aluminum dincphthenate andesters, in inhibiting piston ring sticking Lauson engine, jackgtFtemgOil N aphthenate Ester g g 562 hours to cause ring sticking Western SAE80. N n None 30 D 17 Al dinaph. (270 M. W. acids 1% diamyl tartrate. 90+Do 1 Al dmeph. (340 M. w. acids do 60 Do 1% Mg. naph. (270 M. W. acids00+ Do 1% Mg. mph. (340 M. W. acids do 10 (Plus sign indicates ringsticking had not yet occurred.)

the hot period the speed was'2500 R. P. M. (50 miles per hour), and theload was 25 horsepower. Both copper-lead and cadmium-silver hearingswere provided in the engine to obtain accurate comparative data. Onlythe weight losses of hearing metals during the last two thirds of therun were considered, since the initial wear rate is entirely out of linewith that of the greater portion of the run. The data thus obtained aremore representative oi long operatiing periods.

The results of thQEaGDfiiD-Q tests show that tartrates are veryefi'ective in inhibiting wear of hearings with oils containing aluminumaphthenate. 7

To ascertain the efiectiveness of oils containing both naphthenates andesters for inhibiting piston ring sticking, tests were run in Lausonengines todetermine the time necessary to cause piston ring stickingunder highly adverse condiinvention prevented ring sticking for two,three or more times as long.

The chemical mechanisms by which the results of this invention areobtained have not been established and are not well understood. Metalnaphthenates appear to catalyze corrosion effects in oils. The estersinhibit or offset this catalytic action by a phenomenon which has beendiscovered by the present inventors but which they are unable,definitely, to explain. The phenomenon of corrosion inhibiting appearsto result from some peculiar action which converts the bearing metal toa passive state after an initial induc tion period. This latter fact isillustrated by the following comparative data:

tions. These engines are of the gasoline type and Strip corrosion-totalweight loss grams copper-lead at 300 Test No. Oil Naphthenate Ester 24hours 48 hours 72 hours 1%Al dinaph.. .0189 .0359 .0573 o .0085 .0198.0307 3 0158 0170 0158 0136 .0181 .0151 5'" 0138 .0758 1092 Stripsdipped in straight dibutyl tartrate before start of test.

Oil changed very 24 hours. "Specimens every 24 hours.

Examination of the above data shows that dipping the specimen in dibutyltartrate markedly reduced .corrosion; that changing the oil every ishours had no effect on the corrosiveness of the oil containing both thenaphthenate and the ester; and that when the bearing strip specimenswere changed every 24 hours, the ester showed substantially ,nocorrosion inhibiting action.

These facts indicatethat the'metal surface mustsidered when compoundingoils according to this invention is the presence of free acid in theesters. Tests with tartrates indicate that best results are obtainedwhen the free acid content of the ester is low. It is thereforepreferred to use esters having a neutralization number of no more thanapproximately 20. r

Measurable improvements in the properties of the compounded oil areobtained with as little 0.1% of the ester, but approximately 0.5%, andpreferably. as much as 1.0%, is required to obtain adequate reduction ofcorrosivity in the compounded oil for the purpose of this invention.More 'than 10% is regarded asunnecessary.

The present invention is applicable in its broader aspects to oilscompounded with many oil soluble metal salts of organic acids. Theinvention appears at present to find its greatest utility in oilscontaining metal salts of organic carboxylic acids, and particularly inoilsv containing metal naphthenates capable of inhibiting piston ringsticking. Such metal naphthenates are aluminum, zinc, magnesium, cobalt,cadmium and manganese naphthenates. It is apparent that the particularester and the particular metal salts must be selected with variousfactors in mind,

such as the service to be encountered and the type of bearings inengines to be lubricated if the maximum benefits of the invention are tobe obtained. 4

While the character of the invention has been given in detail andnumerous illustrative examinvention which is of the scope of the claimsappended hereto.

We claim:

1. A compounded mineral oil containing an addition agent in an amountnormally-sumcient to substantially increase the corrosivity of a mineral011, said addition agent being a metalsalt'of an organic acid andselected'from the group of compounds which increase the corrosivity ofhydrocarbon oils tohearing metals such as copperlead mixturesandcadmium-silver alloys, and a small amount of an organic hydroxy e'sterhaving at least one hydroxyl group no more than two carbon atoms removedfrom a carboxyl group of said ester whereby the corrosivity f thempounded oil is materially reduced.

2. A compounded mineral oil as defined in claim 1, in-which the ester isan alpha hydrcay ester of. the type formula in which R1 and R2 representan alkyl, aryl, aralky'l or cyclic non-benzenoid group.

3. A compounded mineral oil as defined in claim 1, in which the ester isa beta hydroxy ester of the type formula in which R1 and R2 represent analkyl, aryl, aralkyl or cyclic non-benzenoid group,

4. A compounded mineral oil as defined in claim 1, in which the ester isa beta hydroxy ester of the type formula in which R1 and R2 represent analkyl, and, oralkyl or cyclic non-benzenoid group.

5. A compounded lubricating oil containing an oil-soluble metal salt ofan organic carboxylic acid in an amount normally suflicient to 51metals-,- tially increase the corrosivity of said oil to hearing metalssuch as copper-lead mixtures and cadmium-silver alloys, and an organichydroxy ester having at least one hydroxyl group no more than two carbonatoms from a carboxyl group of said ester, said hydroxy ester. beingpresent in an amount sumcient to materially inhibit the corrosivity ofthe'compounded oil.

'6; A compounded lubricating oil as defined inclaim 5, in which theester is an alpha hydroxy ester of the type formula ar-on o-ro -an inwhich R1 and R2 represent an alkyl, aryl, aralin which R1 and R2represent an alkyl, oralkyl or cyclic non-benzenoid group.

8. A compounded lubricating oil as defined in claim 5, in which theester is a beta hydroxy ester of the type formula al-cn-om-c-o-u,

in which R1 and R2 represent an alkyl, aryl, aralkyl or cyclicnon-benzenoid group 9. A compounded lubricating oil containing a smallamount of a naphthenate selected from the group consisting of aluminum,zinc, magnesium, cobalt, cadmium and manganese naphthenate, saidnaphthenate being present in an amount suiilcient to substantiallyincrease the corrosivity of the oil to. bearing metals such ascopper-lead mixtures and cadmium-silver alloys, and from approximately0.1% to approximately 10% of an organic hydroxy ester having at leastone hydroxyl group no more than two carbon atoms removed from a carboxylgroup of said est-er.

10. A compounded lubricating oil as defined in v claim 9, in which theester is an alpha hydroxy ester of the type formula m-cm-g-o-m in whichR1 and R2 represent an alkyl, aryl, aralkyl or cyclic non-benzenoidgroup.

11. A compounded lubricating oil as defined in claim 9, in which theester is a beta hydroxy ester of the type .formula m-o-o-cm-oH-m inwhich R1 and R2 represent an alkyl, aryl, aral-- kyl or cyclicnon-benzenoid group.

12. A compounded lubricating oil as defined in claim 9, in which theester is a beta hydroxy ester of the type formula .Rr-CH-CHa-C-O-Ra 'inwhich R1 and R2 represent an alkyl, aryl, aralkyl or cyclicnon-benzenoid group.

13. A compounded lubricating oil as defined in claim 9, in which theester is a tartrate.

14. A compounded lubricating oil as defined in claim 9, in which theester is a tartrate, and the naphthenate is an aluminum naphthenate.

15. A compounded lubricating oil as defined in claim 9, in which theester is a tartrate, and the naphthenate is magnesium naphthenate.

16. A compounded .mineral oil containing an aluminum salt of a fattyacid inan amount suificient to normally increase the corrosivity of saidoil and an organic hydroxy ester, having at least one hydroxyl group nomore than two carbon atoms removed from a carboxyl group of .said

increased corrosivity.

ester, said ester being present in an amount sufficient to materiallyinhibit said increased corrosivity.

17. A compounded lubricatirig oil containing a metal salt of an organiccarboxylic acid in an amount sufliciently to normally increase thecorrosivity of said oil and an oil soluble tartrate, in an amountsufiiciently to materially inhibit said 18. In a method of lubricatingbearing surfaces which comprises maintaining between the hearingsurfaces, one of which is a bearing metal selected from the groupconsisting of cadmiumsilver alloy and copper-lead mixtures, a film of acompounded lubricating oil containing a small amount of a metalnaphthenate which oil would normally tend to corrode said bearing metal,the

step of inhibiting the corrosive action of the cornpounded oil on saidbearing by incorporating therein a minor proportion of an organic ester,

having at least one hydroxyl group no more than two carbon atoms removedfrom a carboxyl group of said ester, said minor proportion ofestercomprising at least 0.1% by weight of the lubricating oil.

19, In a method of lubricating bearing surfaces which comprisesmaintaining between the bearing surfaces, one of which isa bearing metalselected from the group consisting of cadmium-silver alloy andcopper-lead mixtures, a film of a compounded lubricating oil containinga small amount of a metal naphthenate selected from the group c911".

sisting of aluminum, zinc, magnesium, cobalt, cadmium and manganese'naphthenates which compounded oil would normally tend to corrode saidbearing metal, the step of inhibiting the cor rosive'action of the oilon said bearing by incorporating therein aminor proportion of an organicester having at least one hydroxyl group no more than two carbon atomsremoved from a carboxyl group of said ester, said minor proportion ofester comprising at least 0.1% by weight of the lubricating all.

A compounded mineral oil as defined in claim 1, in which the proportionofhydroxy ester is from approximately 0.1% to approximately 10% byweight based on the mineral oil.

A compounded lubricating oil 'as defined in claim 5, in which theproportion of'hydroxy ester is from approximately 0.1% to approximately10% by weight based on the mineral oil.

22. In a method of lubricating bearing surfaces which comprisesmaintaining between the hearing suriaces, one of which is a-bearingmetal selected from the group consisting of cadmiumsilver alloys andcopper-lead mixtures, a film of a compounded lubricating oil normallytending to corrode said bearing metal and containing an additionagent-selected from the group of metal salts of an organic acid whichsubstantially increase the corrosivity of said oil to said bearings,

the step of inhibiting the corrosive action of the compounded oil onsaid bearing by incorporating therein a minor proportion of an organicester having at least one hydroxyl group no more than I two carbon atomsremoved from a carboxyl group p of said ester, said minor proportion ofester comprising at least 0.1% by weight of the lubricating oil.

23. A compounded lubricating oil containing a small amount ofa metalnaphthenate suflicient to substantially increase the corrosivity of theoil te bearing metals such as copper-lead mixtures or cadmium-silveralloys, and from approximately 0.1% to 10% of an organic hydroxv esterhaving at least one hydroxyl group no more than two carbon atoms removedfrom a carboxyl group of said ester.

24. A compounded lubricant comprising a mineral lubricating 011containing a small proportion of a metal salt of an organic acid in anamount sufficient to substantially increase the corrosivity of thelubricating oil to bearing metals, and from approximately 0.1% to 10% ofan organic hydreary ester having at least onehydroxyl group no more thantwo carbon atoms removed from" a carboml group of said ester.

25. A compounded liquid-lubricant comprising a mineral oil containing ametal salt of an organic acid in an amount sufllcient substantially toincrease the corrosivity of the lubricant to bearin metals, such ascopper-lead mixtures and cadmium silver alloys, and approximately 1% ofan ester having at least one hydroxyl group no more than two carbonatoms removed from a carboxyl grow. of said ester.

compounded liquid lubricant comprising a mineral oil containing anoil-soluble metal salt oi an organic carboxylic acid in an amountsuflicient substantially to increasethe corrosivity of loys andcopper-lead mixtures, a film 01 a compounded lubricating oilcontaining'an bil-soluble metal salt of an organic carboxylic acid in anamount which would normally increase the corrosivity of said oil to saidbearing metal, the step of inhibiting the corrosive action of the oil onsaid bearing by incorporating therein from approximately 0.1% toapproximately 10% of an ester having at least one hydroxyl group no morethan two carbon atoms removed from a carboxyl group of said ester.

FRANK W. KAVANAGH. VICTOR N. BORSOFF. ROBERT L. HUMPHREY S.

